1. Field of the Invention
The present invention is directed to the field of optical tracking systems and more specifically to the area of designated point tracking of specifically characterized targets.
2. Description of the Prior Art
The remote tracking of designated targets is discussed in commonly assigned U.S. Pat. No. 4,006,356. That patent utilizes a technique by which an infrared target image is projected onto a plurality of detectors and circularly nutated. By comparing the length of time that each detector outputs a signal attributed to the nutating image, error signals may be developed and the tracker optics can be responsively redirected to track the target along the optical axis line of sight.
Such prior art trackers are adequate for followig point sources of radiant energy, such as the infrared radiation emitted by the engine of a missile or aircraft. However, in more advanced weapon system applications in which high intensity energy is employed to disable and destroy missiles in flight, the energy must be precisely directed to the central control system of a missile in order to be efficiently destructive. The prior art trackers are not constructed to achieve the degree of precision required for such an application.